1. Field of the Invention
The present invention relates to a projection display apparatus that projects an image on a screen.
2. Discussion of the Background
Projection display apparatuses have widely been used, for example, for presentation in spacious rooms. Improvements have been made in lamps for image projection and liquid-crystal panels included in such projection display apparatuses (hereinafter simply referred to as projectors). A diversity of projectors have accordingly been developed to display images of high luminance and high picture quality without any noticeable flickering.
In the case in which a picture image is projected on a screen in a spacious event hall, the use of only one projector may not give the projected image sufficient brightness and may result in unclearness of the projected image.
One method of solving that problem is to provide a plurality of projectors and to project an identical picture image on the same screen with each of the plurality of projectors.
That method, however, disadvantageously requires labor-consuming and time-consuming adjustments including adjustment of contrast in each of the plurality of projectors.